Electric circuit breaker



W. D. BOLLER ETAL ELECTRIC CIRCUIT BREAKER Original Filed June 10, 1948 'IIIIIIIIIIIIA INVENTORS.

Willa U. 8%. Wm M. Z?

ATTORNEYS.

Patented Dec. 15, 1953 ELE TRIC CIRCUIT BREAKER William D. Boller, Milford, Ohio, Warren D.

Berkley, Fort Wayne, Ind., Walter Ernst, Dayton, Ohio, and Edwin W. Landmeier, (lovington, Ky.,

assignors to The Wadsworth Electric Mfg. Co., Covington, Ky., a corporation of Kentucky Original application June 10, 1948, Serial No.

32,204, now Patent N0. 2,618,716, dated November 18, 1952. Divid February 16, 1952,

4 Claims,

This invention relates to circuit breakers, and is concerned primarily with a combination switch and circuit breaker intended to control the circuits in homes and comparabl places.

This application is a division of our United States Patent Application Serial No. 32,204, which was filed June 10, 1948, for Electric Circuit Breaker, and which is now issued as United States Patent No. 2,618,716.

At the present time, the electrical installations for homes, business establishments, and other places making use of the current supply that is made available by the electric companies includes one or mor circuits, each. of which embraces a fuse and sometimes a switch associated therewith. When the circuit is overloaded or a short circuit develops, the fuse burns out in a well-known manner and must. be replaced before service can be restored.

lhe present invention has in view as its foremost objective the provision of a combination switch and circuit breaker which is intended to replace the fuse an switch heretofore employed in controlling such circuits.

Under practical conditions, a plurality of circults are ordinarily included in electrical installations of the type with which this invention is concerned and a further object of the invention is. the. p ovision of a combination circuit breaker and witch. which i usce t ble of. b ng a mbled. in multiple or gangs with each unit contrelline 1: Cirmlit.v

In; the known combination units of the type intended to be imprQVed by this invention, it has been the practice to provide a pair of contacts for controlling the circuit. When these contacts are in engagement, the circuit is closed and when they are Spaced apart, the circuit is open. Usually one of these contacts is fixed and the other is movable. The present invention has in view as an important object the provision of a combination switch and circuit breaker of th type indicated in which both of the contacts are movable. This arrangement presents certain definite advantages. It is possible to provide for the movement of one contact into opened or closed position under the influence of a manually operable, lever while the other contact is placed under the control of the circuit conditions so as to be moved into opened position under overload or short circuiting conditions. This latter contact may be moved back into circuit closing position under the influence of the manually operable lever.

To the end of keeping the contacting surfaces clean a further object of the invention is the proed and this application Serial No. 274,245

vision of a combination switch and circuit breaker of th type indicated in which the contacts are separated with a wiping action in contrast to a direct pull apart.

In circuit breakers of the type with which this invention is concerned, the opening of the contacts is placed under the control of a bimetallic thermostat together with a so-called rupture magnet that is affected by the current conditions to vary the strength thereof. The bimetallic thermostat is heated by overload conditions and when a predetermined condition is reached opens the contacts, whereas the rupture magnet is affected by a short circuit or other comparable instantaneous condition to immediately open the contacts. It has been the practice to mount the rupture magnet on the thermostat so that it is movable therewith. However, the present invention contemplates mounting of the rupture magnet in a fixed position in the casing and an armature which cooperates therewith is carried by a latch which controls relative movement of the contacts. This arrangement presents certain advantages not only as to ease of assembly but also in sureness of operation. With this arrangement, the rupture magnet is mounted with no physical connection between it and the bimetallic thermostat.

Still another object of the invention is the provision, in a combination switch and circuit breaker of the type aforesaid, of a novel assembly of a latch, keeper piece, and, rivets which is highly simplified as compared to anything heretofore provided for this purpose.

Various other more detailed objects and advantages of the invention such as arise in carrying out the above noted ideas in a practical embodiment will in part become apparent and in part be hereinafter stated as the description of the invention proceeds.

For a full and more complete understanding of the invention reference may be had to the following description and accompanying drawings wherein:

Figure l is a longitudinal vertical section, taken on the line I-: of Figure 3, through a third modification and depicts the position of the contacts as normally closed but brings out. in dotted lines the positionof the contacts and; associated parts when the switch. is-manually opened;

Figure 2 is a-iragmentarysection of the combination switch and circuit breaker of Figure 1, taken onthe line 2-2- of Figure 3', with the parts in rupture position caused'bycircuit conditions;

Figure 3 is a compound vertical cross section through the unit of Figures 1 and 2, being taken about on the planes represented by the lines 3-3 of Figure 1;

Figure 4 is an enlarged detailed view in perspective bringing out the anchorage for the bimetallic thermostat of the unit shown in Figures 1, 2, and 3.

The switch and circuit breaker unit shown in the drawings is housed in the usual casing and cover assembly in which are mounted the .ter-

minal plates I69 and I65. The top wall of the casing represented at I66 is formed with an opening I61 in which is pivotally mounted an operating lever I68 which is of insulating material.

Referring to Figure 3 it will be noted that a central plate I69 is imbedded in the lever E68 and on each side of the plate I69 are outer plates I19 and HI. These outer plates I19 and I1! are joined by a flange 12 which is eiiective during the reset operation as will be later described.

A contact carrier 513 is pivotally connected as represented at I19 to the central plate I69. Outstanding from each side of the carrier 513 are a pair of ears H5 and I16 to each of which is anchored one end of the tension coil springs I11 and I18, respectively.

The upper ends of the springs E11 and 518 are anchored to the casing and cover structure as represented at I19 and IS. The tendency of the springs Il'i and IE9 is to bias the contact carrier 5'53 in one direction or the other depending on which side of the center It' l they are located.

The lower end of the carrier H3 is provided with a contact I8! which is located within the efiective zone of a permanent magnet i8? which is included for arc suppressing purposes as above pointed out. The casing structure is provided with a pair of stop members I88 and I89 which limit the movement of the carrier IW. A flexible connector I85 connects the terminal plate I64 to the contact carrier I13.

A rocker I89 is pivotally mounted as indicated at I61 to the casing structure and at its upper endhas an arm E38 which is adapted to be engaged by the flange I12 for the reset operation. The lower end of the rocker I89 carries a contact I89 which is complemental to and engages the contact I8I. A tension coil spring I99 has its upper end secured to the casing structure as shown at IQI and its lower end secured to the rocker as indicated at I82. This spring exerts a tendency normally urging the rocker M6 in a counterclockwise direction. The rocker idS is provided with a stop in the form of a flange I93 which is normally engaged by a detent I9 3 carried at the end of a spring latch I95.

The bimetallic thermostat 96 has one end anchored to the casing structure by the anchoring member which is shown in detail in Figure 4 and which is designated I91. It will be seen that the ends of the thermostat I96 may be inserted between the fingers I98 which are alternately struck from a sheet of metal from which the member I91 is formed. After the insertion the fingers may be compressed over the end of the thermostat to effect a firm anchorage.

The outer free end of the thermostat I96 engages the detent I94 as illustrated and when the thermostat has been afiected as by a predetera mined overload condition it will urge the detent I94 downwardly out of the path of the stop I93. A flexible connector I99 connects the rocker I86 to the thermostat I96. A magnet is shown at 290 as mounted in the casing structure and this magnet is provided with an armature 20I the free end of which engages the detent I94. A coil 292 is wound about the magnet 290 and one end of this coil is connected by a connector 283 with the thermostat I96. The other end of the coil 202 is connected by a connector 284 with the terminal plate I65. A stop for limiting movement of the rocker I86 in a counterclockwise direction is shown at 295 and is carried by the casing structure.

Operation of the device Figure 1 depicts in full line the circuit closed passage in which the contacts I8I and I89 are in engagement. In this position current flows from the terminal plate I65 through connector 204, coil 282, and connector 203 to one end of the thermostat I96, then passes through the thermostat to the other end, and from there through connector I99 to the rocker I86, from the rocker I86 it passes through contacts I8I and I89 to the carrier I13, and from the latter through the connector I to the terminal plate I64.

When the circuit is to be manually opened the lever I68 is swung into the dotted line position illustrated in Figure 1. During this movement the springs I11 and I18 pass to the opposite side of the center I19 and therefore bias the carrier I13 so as to move the contact I8! away from the contact I89. This opens the circuit. To close the circuit all that is necessary is to swing the lever back to the full line position illustrated, which again causes the springs I11 and I18 to pass dead center and bias the carrier I13 to urge the contacts into engagement.

When a predetermined circuit condition, which may be either a short circuit which afiects the magnet 299 to draw the armature 21H toward it, or an overload which afiects the thermostat I96, the detent I99 is moved out of the path of the stop I93. The spring I96 is now rendered effective to move the rocker in a counterclockwise direction and thus draw the contact I89 away from the contact I8I. This movement is limited by the stop 205 and when the carrier engages this stop the arms I88 will be substantially in engagement with the reset flange I12. When the circuit condition has been removed the switch is reset by first swinging the lever I68 over into the dotted line position of Figure 1. This movement is transmitted through the flange I12 and arm I88 to the rocker I86 to move the latter in a clockwise direction and again bring the stop I93 against the detent I94. After this reset operation has been carried out the circuit is closed by again swinging the lever I68 into the full line position which will bring the contact I8I into engagement with the contact I89.

What is claimed is:

l. A circuit breaker comprising, a casing, a

imanually operable lever pivotally mounted in said casing; a plate rigidly embedded in said lever and projecting from the end thereof within said casing, a contact carrier pivotally mounted on said plate, a pivotally mounted rocker, coop-erable contacts respectively carried by said rocker and said contact carrier, a tension spring extending from said contact carrier to said casing, the pivot point at which the contact carrier is connected to said plate being shiitable in response to movements of said manually operable lever to respective overenter positions in relation to said spring for actuation of the contact carried by said carrier toward and from the contact carried by said rocker, the said rocker being biased for independcut disengagement with the contact carrier, latch means releasable in response to overload conditions for restraining the rocker against contact disengagement movement, the said rocker having a resetting ear, plate members embedded in said operating lever at opposite sides of the plate member thereof to which the contact carrier is pivotally mounted, and a bar member extending across the latter said plate members in position to engage the resetting ear of said rocker upon actuation of said manually operable lever following release of said rocker by said latch means.

2. A circuit breaker comprising, a casing, a manually operable lever pivotally mounted in said casing, a plate rigidly embedded in said lever and projecting from the inner end thereof, a contact carrier pivotally mounted on said plate, a pivotally mounted rocker, cooperable contacts respeotively carried by said rocker and said contact carrier, tension springs extending in parallelism from said contact carrier to said casing at opposite sides of said contact carrier, the pivot point at which the contact carrier is connected to said plate being shiftable in response to movements of said manually operable lever to respective overcenter positions in relation to said springs, for actuation of the contact carrier toward and from the contact carried by said rocker, the said rocker being biased for independent disengagement of the contact carrier, latch means releasable in response to overload conditions for restraining the rocker against contact disengagement movement, the said rocker having a resetting ear, plate members embedded in said operating lever at opposite sides of the plate member thereof to which the contact carrier is pivotally mounted, and a bar member extending from one side plate mem 3e1- to the other in straddling relation to the center plate for engaging the resetting ear of said rocker upon actuation of said manually operable lever following release of said rocker by said latch means.

3. A circuit breaker comprising, a casing, a manually operable lever pivotally mounted in said casing, said lever having a plate rigidly embedded therein and having a portion projecting from an end thereof Within said casing, a contact carrier pivotally mounted to the projecting portion of said plate, a rocker movably mounted in said casing, said rocker and contact carrier having cooperable contacts, spring means residing in operative engagement with said contact carrier for biasing it toward and from the contact of said rocker by overcenter forces in response to pivotal movement of said lever, means for operating said rocker including a latch normally holding said rocker against movement but being releasable in response to circuit overload conditions, and means for resetting the rocker after release thereof by said latch, including a resetting ear extending from said rocker, and plate members having portions thereof embedded rigidly in said lever at opposite sides of the said first plate member, said latter plate members having projected portions, and a flange portion in cross connection with the said extended portions, in position for engaging the resetting ear or said rocker arm upon actuation of said manually operable lever.

4. An electric circuit breaker comprising, a rocker member biased for automatic movement, releasable means responsive to circuit overload conditions normally preventing such movement, a contact carrier having a contact engageable with said rocker member, said contact carrier being movable independently of said rocker member, and means for independently moving said contact carrier and for selectively resetting said rocker member, including a pivotally mounted manual lever of insulating material having a plate partially embedded therein, a pivotal interconnection between the portion of said plate which is not embedded in said lever and said contact carrier, and a U-shaped assembly comprising plate portions which are embedded in said lever at opposite sides of said first named plate and an interconnecting portion extending across the first named plate, the said rocker having a portion thereof which is engageable by the said interconnecting portion for resetting the said rocker arm by movement of said pivotally mounted lever.

WILLIAM D. BOLLER. WARREN D. BERKLEY. WALTER ERNST. EDWIN W. LANDMEIER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,190,517 Jennings Feb. 13, 1940 2,240,189 Linde et al Apr. 29, 1941 2,367,382 Taylor Jan. 16, 1945 

